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Beehives contain multitudes

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KAYTE YOUNG:  From WFIU in Bloomington, Indiana, this is Earth Eats and I'm your host, Kayte Young.

IRENE GARCIA NEWTON:  So, I like to say that bees are just like us. So, bees have a society and they live in a built environment, their little house, just like we have a little house and they communicate with each other through dance. I don't know if we communicate through dance, but I think dance is also a thing that humans do.

KAYTE YOUNG:  This week on the show, we're talking with microbiologist, Irene Garcia Newton about the beloved honeybee. We learn about the various roles within a hive and how the diet of a bee determines, well everything. Stay with us.

KAYTE YOUNG:  Thanks for listening to Earth Eats, I'm Kayte Young.

KAYTE YOUNG:  I am a backyard beekeeper, I have been for almost six years. I'm not exactly a successful beekeeper, but I am devoted. I don't keep bees for the honey, I don't even keep bees for their pollinating power in my garden. I keep them because they are fascinating to observe. If you know a lot about bees, you'll probably find this conversation interesting, because of the detailed information and discovery from a biologist who studies symbiosis and bee nutrition. If you don't know much about bees, now's your chance to learn more about these complex creatures who play a crucial role in our food system. My guest is Irene Garcia Newton, she's a professor of biology at Indiana University and her current research is focused on the honeybee.

KAYTE YOUNG:  I wanted to start first by kind of making a distinction between backyard beekeeping and agricultural beekeeping and explain what agricultural beekeeping or commercial beekeeping is.

IRENE GARCIA NEWTON:  Sure. So, honeybees are a domesticated insect. They're not native to North America. So, apis mellifera mellifera, which is the European honeybee strain that people use here is the most important agricultural insect in the sense that it is what we rely on for pollination of our things we like to eat. So, anything in the grocery store that you find delicious is probably pollinated by a bee and otherwise without them and without their efforts for pollination, we would be limited in our diversity and abundance of food. But they were introduced and they are heavily managed. So, when people ask me this question of thinking about bees and their relation to us as humans and our environment, well they're not native animals and you can think of them as kind of like chickens, you have to feed them, you have to give them vaccinations, check them for diseases, same is true for bees.

IRENE GARCIA NEWTON:  So, large scale commercial beekeepers and also hobbyists, spend a lot of time maintaining their colonies, provisioning them with food if they need it, if there's a dearth. Giving them supplements if they need it. Adding some medicines, should it be the case that they require it and monitoring them for parasites. Large scale commercial beekeepers keep hundreds if not thousands of colonies and most large-scale beekeeping farms are involved in trucking their bees across the United States as different crops become available. So, as blueberries start blooming in Michigan, then bees will be brought out there. Then when the almonds come out in California, they'll come out there and then Washington State, if the apples come out, they'll truck the bees there. So, the bees spend a lot of time migrating in this way on the backs of trucks and the way they do that is they just box them up at night, when the bees have all come home to sleep and then put them on the back of a truck and get them going to their next location.

IRENE GARCIA NEWTON:  And hobbyists, I would say, probably spend a lot more time taking care of their colonies, a lot more time thinking about them, because it's their hobby and it's fun for them. A large-scale beekeeper is trying to minimize the time that they spend on each of these individual colonies, because there's a lot of them. So, maybe they will spend a total of five minutes on a colony per year.

KAYTE YOUNG:  So, when you were listing all those things that a beekeeper needs to provide, one of the most important ones is housing.

IRENE GARCIA NEWTON:  The box, yeah.

KAYTE YOUNG:  Like shelter.

IRENE GARCIA NEWTON:  Yes. So, I like to say that bees are just like us. So, bees have a society and they live in a built environment, which we call the hive. So, the boxes that we build for them. Or if they were naturally existing in Europe, for example, or feral colonies in the States in a hole in a tree and they build out this wax comb they make themselves, to store all of their provisions and to rear their young inside of these little hexagonal shapes. So, they have a built environment, their little house, just like we have a little house and they communicate with each other through dance. I don't know if we communicate through dance, but I think dance is also a thing that humans do. And they also forage for natural resources like nectar and pollen and then ferment them to make them more nutritious and to also preserve them and that's something that we do too.

KAYTE YOUNG:  So, maybe we could talk now about their diet and about what kinds of products they make. That's one of the things that I find so fascinating about bees is that they make so many things.

IRENE GARCIA NEWTON:  Oh, they make lots and lots of things.

KAYTE YOUNG:  Not just honey.

IRENE GARCIA NEWTON:  Well, yes, of course. We already mentioned the wax that they make to create the cells that they store everything in. They also harvest resins to make propolis which is this compound that they use as both an adhesive in the colony or cohesive and also to try and limit the growth of some unwanted microbes in the colonies. So, it has an antimicrobial purpose in addition. They harvest nectar to make honey. So, people know them as honeybees because of that property and that's an important product that's commercially used. But then in addition, they harvest pollen and pollen is the source of their proteins and lipids and if you have thought about it before, if you've had any experience with pollen, you might know that it is a difficult thing to get nutrition from. Sporopollenin is the polymer that covers the surface of the pollen, it's difficult to break apart. It's difficult to digest.

IRENE GARCIA NEWTON:  So, similarly to us, we eat fiber in our diet to help us get those intestines moving but a lot of it we ourselves, our physiology can't degrade, but our microbes assist in the degradation of it. For bees it's the same deal, so they can't themselves degrade this pollen, but their microbial community helps them to do so. So, they add microbes to it through regurgitation and then they let it sit for a few days or weeks before eating it. It preserves it, but also it makes it more nutritionally available.

KAYTE YOUNG:  This fermented pollen substance is called bee bread.

IRENE GARCIA NEWTON:  It's called bee bread. So, they make it and they produce this nutritious thing that they consume. Largely in-hive bees are eating this and this is the source of nutrition for them to rear their young, the next generation of bees.

KAYTE YOUNG:  So, the young aren't eating the honey that they're producing?

IRENE GARCIA NEWTON:  So, the bee colony is a really interesting mix of different castes and also different tasks. So, the workers, which are the bees that probably your audience more likely has interacted with, the worker bees are sterile females, who go out and do all the foraging. So, that worker caste has a task of foraging. Those are the oldest of the worker bees in the colony and they can be months old. Then the younger workers in the colony, also sterile females, are tasked with rearing the next generation of babies. And so, their job is to go cell to cell and look for these little baby grubs and feed them if they need to be fed. They have a special gland called the hypopharyngeal gland that becomes very large in that particular task and this produces a glandular secretion called royal jelly that you may have heard of and we can talk more about, and it's really a nutritious and important content of food for the Queen.

IRENE GARCIA NEWTON:  So then, the even younger newly emerged worker bees that come out, also sterile females, will be tasked with things like clean up. And so, as they age into these different tasks, the worker bees have different ways that they interact with their colony members, different ways that they interact with their food. So, the in-hive bees who are doing this extremely physiologically difficult job of generating nutrition for the baby bees, they eat a pollen diet and honey diet. The foragers that are out foraging for resources, they have to fly a long distance and they're getting a lot of energy from the nectar that they forage and from honey. The baby bees are they're developing, depending on whether they're going to be Queens or workers, they will be fed a different diet.

KAYTE YOUNG:  So wild.

IRENE GARCIA NEWTON:  The three main castes of the bees then are the Queen, she's the only reproductive member of the colony, the only one who's capable of reproducing. Then there are the workers that have different tasks that they perform based on their age and then there are the drone bees, or the males. The Queen comes from an egg that is a fertilized egg, so she could be a worker if she's fed a worker diet or she can turn into a Queen if she's fed royal jelly.

KAYTE YOUNG:  I'm tempted to ask more about the drones, but I'm just going to skip that for the moment. So, what are the larva fed?

IRENE GARCIA NEWTON:  One of the most fascinating things about bees is this plasticity in their development. This fact that the same genome, the genetically identical egg can turn into a worker that is effectively sterile, lives a few months, is under the control of the Queen, or she can turn into a Queen who lives years and is reproductively capable, much bigger than workers and another important distinction is that if you've ever been stung by a honey bee, you know that they eviscerate themselves if they sting you. So, along with their stinger, the worker digestive tract comes along with it, and so the worker can sting you one time. So, she's really taking her one shot. The Queen can sting you as many times as she wants. [LAUGHS] So, very big physiological difference.

KAYTE YOUNG:  I never even thought about being stung by a Queen bee. [LAUGHS] It just never occurred to me.

IRENE GARCIA NEWTON:  You don't want to be either. [LAUGHS]


IRENE GARCIA NEWTON:  Because as she sends off alarm pheromone, then all of the other bees are going to come get you. But regardless, these big differences are a result of the developmental environment. So, the environment experienced by the larva in these days as it is turning into a pupa and then closing as an adult, are the most important at determining the fate of this organism and if this larval bee is fed a highly nutritious diet that's comprised of royal jelly, then it will turn into a Queen and if it is fed a less nutritious diet, we call worker diet, a combination of pollen and nectar, foraged resources, a little bit of royal jelly, it will turn into a worker.

KAYTE YOUNG:  Okay, so they do get a little bit of the royal jelly.

IRENE GARCIA NEWTON:  They do get a little bit of royal jelly.

KAYTE YOUNG:  So, it's really just a matter of amount. That's so fascinating.

IRENE GARCIA NEWTON:  That's right, and actually there have been many studies. Gosh, I want to say decades and decades, people have been trying to figure out what is the secret sauce, what turns Queens into Queens. And there have been many crazy hypothesis out there, everything from "It's this specific protein that we've identified." Turns out that was not true. Or it has to do with the presence of certain things in the pollen that are inhibiting the development of Queens. Also not true. You can change the amount of nutrition that a larval bee gets in the lab and generate a Queen. So just give her more and she will become a Queen.

KAYTE YOUNG:  Wow. Sounds like though that there are still some mysteries about bees. [LAUGHS]

IRENE GARCIA NEWTON:  Oh, sure there are, yes.

KAYTE YOUNG:  Could you walk us through maybe the early part of the life cycle of a bee?

IRENE GARCIA NEWTON:  So, Queen, her job is to lay eggs. So, she'll lay hundreds or thousands, if you're lucky, eggs a day and she lays them in a really neat pattern, because you can see her swirl around that comb, so the youngest ones are in the center, or the first ones she lays are in the center, so I guess those will be older. And then she keeps going around and around and around in a circle and those little eggs hatch into first instar larvae and their first meal is going to be given to them by their sisters. So, the older generation of worker bees, called nurse bees, and these nurse bees are feeding them their first meal, which has royal jelly in it. And royal jelly is a glandular secretion, it's akin to mother's milk. It's this complex nutrient rich thing that we know a little bit about but not too much about. Always more mysteries in what's in royal jelly. And so, the insect is making this for its sister. And then the little baby larva eats it and then if it's going to be a worker bee, it will have a diet that's primarily foraged resources like pollen and nectar. And if it's going to be a Queen bee, it'll be given more royal jelly and that difference in nutrition will set the trajectory of these two paths for a developing bee.

IRENE GARCIA NEWTON:  And so then, days pass and there are actually a different number of days that they spend as larvae and as pupae if they're going to be workers or if they're going to be Queens. And then after that developmental period, they're whole metabolize insects just like butterflies, and so they have a form like a chrysalis which we call a pupae and all of their adult organs will develop, the adult wings, the adult eyes will develop during that time and then they'll emerge. And one of the first things that they do when they emerge is they actually chew out of the little cell that the workers have capped them in. So, they eat a little bit of that wax cap and then they interact with their nest mates next to each other or the nurse bees that are tending them and they will clean out their cell. And in this way they are inoculated with their microbial community. So, when they first come out, they don't have any associated microbes, because they've gone through this huge developmental change of becoming an adult insect and all of their cuticular lining of every single part of them is shed.

IRENE GARCIA NEWTON:  So, they have to be reinoculated and they do that socially in the colony with access to their nest mates and with access to the built environment around them that is also covered in bee associated microbes. And then as soon as they emerge, they are assigned to tasks in the colony and they mature from there.

KAYTE YOUNG:  So, what they got in their larval stage, it's not what's going to protect them?

IRENE GARCIA NEWTON:  That's absolutely true. So, almost all animals are born sterile, in the sense that they have no microbes. So, if a little frog egg hatches in the water, when it initially hatches, it is sterile also, because it's been protected inside of that egg from any microbes. The exception to that are maternally transmitted intracellular bacteria for which insects are famous. But for now, I think it's simple to say that most animals are born sterile and bees are no exception, the eggs when they hatch, they first are inoculated with the food that their sisters are giving them. So, that little bolus of royal jelly comes with an important microbe that my lab works on called bombella apis and that microbe gives them more nutrition and protects them from fungal pathogens as they're developing.

IRENE GARCIA NEWTON:  Then when they go through this metamorphosis, they shed their gut lining, which means that they have to be reinoculated with their own bacteria and with bacteria from their sisters and that physiology that they have now is different and their diet is different, so the community is going to be different.

KAYTE YOUNG:  So, let's go into some of what your lab is studying.

IRENE GARCIA NEWTON:  This bombella apis?

KAYTE YOUNG:  Yeah, bombella apis.

IRENE GARCIA NEWTON:  So, we became interested in this microbe a long time ago, back in 2014. We had done a large scale study of the microbiome of Queens, because back then many many people had been studying worker bee microbial communities, because there are thousands of them, so it's pretty easy to sample and you don't kill the colony [LAUGHS] if you kill the Queen. So, you kill the colony if you kill the Queen. So, no one wants to do that. So, it's easier to sample workers. But we worked with a honey bee geneticist and Queen breeder, David Tarpy, and my long time collaborator, Heather Mattila, and we sampled Queens during development. So, the question we asked was really "Does the Queen rearing process, the commercial Queen rearing process change the Queen microbiome?" And that's because I mentioned that honey bees are domesticated in the States, but what I also didn't mention is that we breed Queens routinely, because more recently there's a large incidence of Queen loss in colonies that can lead to colony collapse, and so people want to replenish their colonies with obviously a reproductively capable member of the colony, and so they'll buy a Queen to kind of re-queen a colony for a variety of reasons.

IRENE GARCIA NEWTON:  And the way that Queens are bred commercially is that the Queen breeder will take first instar larvae, so the youngest baby larvae from one colony and graft them into these little wells and put that into a Queenless colony. Now, those workers in the Queenless colonies are overjoyed to see any larva [LAUGHS] and they will immediately start making them Queens, because they recognize that without a Queen they are dead in the water. So, they will turn all of these larvae into Queens, and so you can rear many at the same time. But then after they become pupae, they're transferred to a mating nucleus, so they can mate with the drones in the area and then they're finally in their final colony, so they're sent to the final colony. So, those are four different handling steps in the process and we wondered if the workers that interact with the Queens at each step may influence their microbial trajectory. Turns out it's a very naïve experiment because we didn't think, "Oh, Queens are just physiologically extremely distinct and eat something completely different."

IRENE GARCIA NEWTON:  So, her microbiome doesn't look anything look workers and what we discovered instead in that manuscript was that Queens have this microbial community dominated by a citrobacter named bombella apis and a lactabacilli strains, so having none of the characteristic microbiome that we find associated with worker bees.

KAYTE YOUNG:  I'm going to pause here to make sure this is clear. So, there are Queens who are being raised commercially, which allows them to be studied more easily and the question that Irene Newton's team went in with was, "Would the Queens microbiome be influenced by the particular worker bees she was raised by?" And what they found was that her physiology is just so dramatically different that it looks like nothing like a worker bee. Her microbiome is dominated by bombella apis and lactobacilli strains. That is not the case for worker bees.

IRENE GARCIA NEWTON:  And so that was fascinating and led us to thinking, well, one, what is that microbe doing there? How is it associating with Queens? What benefits might it be providing and why is it that she has this microbial community? And subsequently, my students have been interested in tackling these questions and we asked first whether the royal jelly that the Queen is eating is selecting for this specific microbe. Royal jelly itself, as I mentioned, is this really ill defined nutrient rich complex thing. But it's really really antimicrobial. So, since the time of Socrates, people have known that royal jelly is antimicrobial. Why? They don't know but they know it is. And really, microbes cannot grow in it at all and they will die. But in our hands, what my student Audrey did was have a collection of bombella apis strains she isolated from our colonies and then she also had some other strains that we find associated with bees and she found that the only microbe that can grow in the presence of royal jelly is bombella apis.

IRENE GARCIA NEWTON:  And the only one that can persist in high concentrations of royal jelly is bombella apis. The other microbes have this very nice dose dependent [LAUGHS] drop in viability with addition of royal jelly. So, that really suggested that the reason the Queens have this bombella apis filled gut is because she's eating royal jelly. And larvae, as we know, are also inoculated with royal jelly, so we wondered what role might bombella apis be playing in these environments. So, animals, they're not so good at making their own nutrition. Our metabolisms are really limited. So, we in microbiology use the word auxotrophe to describe a deficiency in the ability to make a particular nutrient that's needed for life. So, be that a vitamin or an amino acid, et cetera, and so animals are auxotrophic for many amino acids, this is what we call the so called essential amino acids. So, they're essential, because we need to eat them.

IRENE GARCIA NEWTON:  So, it's really an animal centric view of the world. Many bacteria can make all of their amino acids and don't have this problem. And so, we rely on those microbes and also on plants to make what we need and then we eat it. So, honeybees are the same, they're also animals and they also have a need for certain amino acids. They use foraged pollen to get their nutrition. So, depending on the plant, the pollen can bury in the content of these essential amino acids. And so, depending on the season, depending on the plant, depending on the worker health, you will have nutrition that varies for the developing bees. What my student, Audrey, discovered is that if bombella apis is in the worker diet, it actually takes the non-essential amino acids, the one the animal can make and turns into them something more valuable, the essential amino acids.

IRENE GARCIA NEWTON:  So, it's essentially up-cycling for the host, up-cycling these amino acids that are needed for the development of the bee, and specifically, an amino acid called lysine, that is really limited in many sources of pollen. So, it does that for the bee and we did experiments in the lab to show that the addition of bombella apis to the food of the bee during the development bolsters against nutritional stress. So, we could drop the amount of nutrition that we were giving the bees by 25% and they would reach the same size if they had their symbiont present. But without their symbiont they were quite small.

KAYTE YOUNG:  What is the symbiont?

IRENE GARCIA NEWTON:  Symbiont. The word symbiont, which I did not define earlier. So, symbiosis is defined as two organisms differently named living together. So, it is meant to encompass a full range of interactions from what you might consider mutualism or the benefit to both partners on one end of the spectrum or a pathogenesis and parasitism and on the other end of the spectrum. So, it just means that bombella apis is associated with the bee.

KAYTE YOUNG:  Okay. That makes sense. And you're referring to it as that rather than as a supplement or as a nutrient, because it's not itself a nutrient, it's what's helping.

IRENE GARCIA NEWTON:  It is a microbe, yes.

KAYTE YOUNG:  Yeah, it's a microbe that's assisting.

IRENE GARCIA NEWTON:  It is own its living entity.

KAYTE YOUNG:  Yeah, that's kind of hard to wrap your mind around if you're not a scientist, I think [LAUGHS] sometimes.

IRENE GARCIA NEWTON:  Well, I don't know if you're familiar with Ed Young's book, I Contain Multitudes? But if you aren't, I suggest you read it, it's an amazing read, and it goes through a bunch of different symbiotic systems including humans, to emphasize that our idea of a self is very narrow and if we really think about what is on our surfaces, in our cells, inside of our guts, on every single part of us, we recognize that we are a community, we're an ecosystem and microbes play an enormous role in our digestion and our nutrition just as they do for the honey bee. Suggest you read it, it's an amazing read, and it goes through a bunch of different symbiotic systems including humans.

KAYTE YOUNG:  Why aren't the bees getting the nutrients that they need to build these amino acids?

IRENE GARCIA NEWTON:  Oh, so animals can't. [LAUGHS] Animals are incapable of making this certain set of amino acids that we call essential. We don't actually have the pathways in our genome to do it. So, you have to get it from your diet, and bees you could say, yes, plants make these, so why don't you go out and eat certain particular plants? But if you or your friends are vegan, you may know that it's actually quite difficult to get the exact complement of amino acids, you have to be thoughtful about it and you have to be intentional about what you eat, because of its amino acid content and if something isn't available, you can choose another option, but it may not be as nutritious. And the same is true for bees. Bees are cosmopolitan pollinators, they rely on a diversity of pollen sources. But more and more, the way we use them for agriculture and our land use patterns have changed the landscape for bees. We no longer have lush diverse prairies in the Mid-West.

IRENE GARCIA NEWTON:  We have really long stretches of mono-culture wind pollinated crops that are really not nutritious for bees. So, it's harder to live as an insect in the world that we've created, especially a pollinator, and even if the bees had access to some diverse sources of pollen, they would need to be able to combine them in the right way to be able to have all the nutrition that they need. So, the microbes assist them in this way by changing amino acids that are not as critical to those that they really need.

KAYTE YOUNG:  So, is your lab looking at introducing this microbe into the colonies to assist them?

IRENE GARCIA NEWTON:  So, years ago now, when we discovered anti-fungal properties of honeybee symbiance, we had started a company called Vitality, because I love puns, and our goal was to develop a pro biotic usage for these honey bee associated microbes. And it is the case that if you go out to any honeybee colony, you could probably isolate a strain of bombella yourself. But what we know from our lab work is that the strains really vary in their ability to perform this mutalistic function. Some strains produce a lot of lysine or a lot of anti-fungal and some strains do not. So, who you have there matters, not just that it is bombella apis.

KAYTE YOUNG:  So, you are developing…?

IRENE GARCIA NEWTON:  Yes. We're developing this as a probiotic for bees. But I'll tell you that, for good reasons, it is difficult to patent a naturally derived organism or a gene. So, I would say that people are hesitant, as they should be, to adding genetically modified materials to their honeybees, because it enters the food chain. Honeybees are pollinators, so they'll necessarily interact with our foods and we eat their honey, so we interact with that. So, people are hesitant to introduce something genetically modified and you cannot patent or protect a naturally derived organism. So, I don't know if it is particularly lucrative. [LAUGHS] So, I would say, we are interested in applications, for sure, and we're interested in helping any beekeepers who are interested in using bombella as a supplement in this way.

KAYTE YOUNG:  Okay, so, patents and commercial viability aside, how would you use this? Say you did have it available and you felt like your colonies needed it, how would you use it?

IRENE GARCIA NEWTON:  Yeah, so I imagine it would work the same way as probiotic supplementation does now for most agricultural animals and that is you would add it into their feed or into their water and bees are supplemented all the time, because of the way that we maintain them. So, you can add bombella to sugar water, or you can add it to pollen patties and then the bees would take it up into their crops and bring it back into the colony and share it with their nest mates and that way it would be disseminated into the colony.

KAYTE YOUNG:  So, it's the mono-culture that is making it so that they're not getting the diversity of the plants that might help them to--

IRENE GARCIA NEWTON:  Yeah, I mean, I think if you just think about how humans have changed the landscape for bees and for other insects. Lawns are king and everyone has their own mono-culture of crop in front of their yard and the backyard too. We plant these mono-cultures in rows, instead of having a lot of diversity around them and there's more and more of us, and so we've consumed more and more of the land available. So, since the 1950s, really, people have noticed a decline in the pollinator viability. Our ability to keep colonies in the US has declined rapidly and there are probably a multitude of factors contributing to it. One of which has to do with floral resources and nutrition. Secondly, the introduction of this parasite called the varroa mite that transmits viruses within the colony and sucks on the fat body and haemolymph of the developing bees.

IRENE GARCIA NEWTON:  And then we have introduction of chemicals and pesticides and herbicides that people heavily use everywhere and which can disorient bees, can make it more difficult for them to get back to their colony and can reduce lifespan. So, there are many reasons why bees are in decline. But I would say all these stressors impinge upon the bee and act synergistically to produce the effect we're seeing and land use patterns are a big one.

KAYTE YOUNG:  So, I had one other question that came up when you were talking about the different stages of the bees and how they raise worker bees or a Queen. Why would a colony raise a Queen if they already have one?

IRENE GARCIA NEWTON:  Yes, it's a very good question. So, it is an absolute monarchy but you can have a coup. [LAUGHS] So, there are a couple of reasons why workers may do this. So, when a colony becomes too big for their hive, then the older Queen will take some of the workers with her and found a new colony somewhere else and the remaining first instar larva are raised to be the new Queen. They raise multiple and the first one to come out is going to be the Queen and she actually systematically goes and kills the others. It's very Game Of Thrones. [LAUGHS] So, she goes and makes sure that there is no competition for her. But sometimes the colony isn't doing well for whatever reason and the workers will always blame the Queen. It is entirely her fault, and so they will determine that it's time to rear a new one and they will supersede her with a new Queen that they will rear then.

KAYTE YOUNG:  Because you were talking about what they're fed determines what they were going to be, I would just think that it would be so rare that they would be raising a Queen. But as someone who has kept bees in my backyard before, I've seen that they do this a lot. They start some.

IRENE GARCIA NEWTON:  They're constantly starting the cells, yes.

KAYTE YOUNG:  I feel like there's always another one. [LAUGHS]

IRENE GARCIA NEWTON:  There's always some plot. There's always some plot, right? Yeah, it is Game Of Thrones. And if you don't go out as a beekeeper and then get rid of those Queen cells.

KAYTE YOUNG:  Which also doesn't feel good. [LAUGHS]

IRENE GARCIA NEWTON:  Does not feel good, does it? No, they're always so very elaborate. Or if the Queen herself doesn't kill the--

KAYTE YOUNG:  Oh, she could go around and--

IRENE GARCIA NEWTON:  She could go around and sting them, yeah, for sure.

KAYTE YOUNG:  What is the word for killing a Queen? Regicide? Apparently, new Queen bees have no problem doing it. For them, I guess, it's kill or be killed. I'm sure professional commercial beekeepers do it all the time as needed, but I personally don't have the stomach for it. I have removed some Queen cells from the hive before they're fully developed. It still felt awful, but I understand it's an important part of hive maintenance. I am endlessly fascinated with all of the hive drama and the stages of development, the many products that come from a worker bee. I told Irene Newton that I envy her work, which allows her to focus her attention on these wondrous creatures. After a short break, we'll learn about how she got into this type of research and what the work in the lab actually looks like. Stay with us.

KAYTE YOUNG:  Kayte Young here. This is Earth Eats and we're back with biologist, Irene Garcia Newton. She started her research on honeybees back in 2010. Here's Irene.

IRENE GARCIA NEWTON:  So, I am a microbiologist with an interest in symbiosis. So, what fascinates me is this idea of, as an organism, as a microbe, if you can personify them, their ecology is another organism. So, that's fascinating to think that your ecology is evolving and responding to you in a way that's not true if you're a microbe that lives on a rock. So, I've always been fascinated by symbiosis and I used to work in deep sea hydrothermal vent systems. So, really quite different. But then I moved into insect hosts, because one, it doesn't require boats and two, they're readily available, and three, they're the most diverse metazoans on the planet. And part of that diversity probably has something to do with the really huge array of microbial associations that insects have. Almost every bug out there has a special symbiont that does something special for it.

IRENE GARCIA NEWTON:  Anything from hardening their cuticles to make them less edible or more protective from predators, to providing them with specific amino acids missing from their diet, to producing chemical cocktails to protect them from others. So, there's a very large panoply of these types of interactions in the insect world that are truly fascinating. And in 2010, I became introduced to the honeybee and the honey bee microbiome and I thought it was a beautiful model in which to study the intersection of society and these behavioral interactions with genetics with the microbial community.

KAYTE YOUNG:  Do bees have multiple symbionts?

IRENE GARCIA NEWTON:  Oh, yes. The word microbiome is this assemblage of different genomic and microbial components that are in an environment. So, microbiome just refers to that group of the massive genetic material that's there. But microbiota are these organisms that are present there, the living microbial entities, be they viruses or bacteria, archaea or even eukaryotic microbes. So, this very diverse group of organisms lives associated with the animal and the bee has a set of primarily bacterial microbial associates that dominate the worker digestive tract and that's been studied for a long time. So, the workers have their own very characteristic and specific microbiota and then the Queen has her own and the drones have their own.

KAYTE YOUNG:  So, what does your research look like now? How do you spend your days?

IRENE GARCIA NEWTON:  I spend my days writing grants, it's not very nice. [LAUGHS] But as you rise in the ranks of the professorship, you do less bench work. But the types of questions that I'm interested in, I mean, you never know where science is going to take you, so I think the umbrella of the questions that I'm interested in are, how do hosts and microbes interact with each other and what are the ramifications to the ecology of the animal, the evolution of the system? That big overarching picture has stayed the same. What changes is the results you get lead you in different directions. I would never have thought that we'd be working on a nutritional symbiont for bees. We didn't know what bombella did and our original work suggested it was largely an anti-fungal protected but when my student, Audrey, first did these experiments and showed that larvae are actually bigger when they have bombella, even if they're nutritionally stressed, that led us in the direction of thinking about what in its genome might be providing these resources? What might it be secreting that might be facilitating this nutritional bolstering?

IRENE GARCIA NEWTON:  So, you just follow things where they go. What we're more interested in now, even in these symbionts of symbionts, right? So, it's kind of like a Matrushka doll, you know the little Russian nesting dolls. You have your honeybee and within the honey bee you have your bacterial associates and within those bacteria you have mobile elements, like phages and plasmas, these little tiny genetic selfish elements that move between microbes and can alter their function in really important ways. Probably the listeners of your podcast have heard of antibiotic resistance cassettes and how antibiotic resistance spreads in microbial populations. Part of the reason why it spreads is it's facilitated by these tiny little mobile elements, these symbionts of symbionts that I'm talking about. So, we're really interested to know about these plasmids and phages found in bombella, how they might be changing the function of bombella in the colony and what they might be conferring and how they evolve across the entire colony.

KAYTE YOUNG:  Okay, so, your work itself might look like grant writing and then thinking about what the research is showing you. But what does the lab work look like? Is it all microscopic? Is there any interaction with the bee colonies?

IRENE GARCIA NEWTON:  Oh, no. Oh gosh, we do everything. We do everything, everything, everything. So, we keep an apiary of colonies up on Bales Road here and we sample from there. We also sample from our long time collaborators at University of Illinois Urbana-Champaign. So, there's a very large bee lab there, they keep thousands of colonies and they can also keep them over the winter. So, that facilitates some of our work. We definitely do in-colony work and colony samples. But then, yes, we bring the samples back to the lab and we isolate microbes, we sequence genomes to understand what is going inside of those microbes. We are pretty well set up to do in-vitro rearing of bees. So, one of the things that my students develop is being able to take larvae from a colony, very young baby first instar larvae and then feed them in the lab without any microbes, so we can rear them in a completely sterile environment and that allows us to add microbes back and ask, "What do these microbes do to development?"

IRENE GARCIA NEWTON:  Then we can challenge the bee in different conditions in a controlled way and ask, "Well how is this process influenced by the presence or absence of the microbe?" So, it can really let us mechanistically dissect how these microbes impinge upon bee health and physiology in a very controlled way.

KAYTE YOUNG:  Wow, that must be really strange having them, raising them in the lab.

IRENE GARCIA NEWTON:  So, we have incubators and they are multi-wall, 48 well plates, with these little cups in them and we put the little bee in there and then your nurse bees would normally be coming by and feeding them every so often, but my students are the nurse bees [LAUGHS] giving them this diet that we make in the lab and seeing how it impacts them through development. But we can rear bees all the way through to adulthood in this way in the lab.

KAYTE YOUNG:  I'm speaking with Irene Garcia Newton, a biologist at Indiana University. She's talking about her research on honeybees and the microbial communities within bee colonies. I mentioned earlier in the conversation that I wanted to come back to the topic of drones, that's what they call the male bees. After a short break, Irene will tell us about what makes drones so special. Stay with us.

KAYTE YOUNG:  This is Earth Eats, I'm Kayte Young and we're back with biologist, Irene Garcia Newton, talking about honeybees.

KAYTE YOUNG:  So, I'm going to go back just a tiny bit, because I didn't ask about the drones before, but I know that listeners are going to be wondering. So, what about the male bees? What's their purpose? [LAUGHS]

IRENE GARCIA NEWTON:  What's their purpose? They have one purpose and that really is to inseminate the Queen. They are produced when Queens are being reared by colonies, so it's a seasonal production and they come from unfertilized eggs. Bees, their sex is determined by whether or not the egg is fertilized. If the egg is fertilized, it'll become a female and that female can be either a worker or a Queen. If the egg is unfertilized, it's a male and it can become a drone. And the drones are very different looking from workers and Queens. They have these enormous pilot sunglasses eyeballs, just huge. Why? Because their only task is to find that Queen and mate with her.

KAYTE YOUNG:  And they're not doing that in the colony?

IRENE GARCIA NEWTON:  No. They are produced in the colony and they fly out and they sense Queen pheromones. So, when a newly emerged Queen is looking for mates, she leaves the colony once on her so-called mating flight. So, this is her one night out and she'll fly out and her pheromones will call all the drones in the area.

KAYTE YOUNG:  So, not just the ones from that colony? It could be all of them.

IRENE GARCIA NEWTON:  No, in fact the goal is to have it be more genetically diverse, not her brothers.

KAYTE YOUNG:  Oh, okay.

IRENE GARCIA NEWTON:  All these drones in the area will come to her and she will mate with them, anywhere from ten to 20 males. The males die after mating with her and she keeps their sperm for her whole life. So, for five years she will keep this diverse sperm stored up and that's what she uses to make the workers in her colony.

KAYTE YOUNG:  And so, most of the eggs that she's going to be laying are going to be fertilized, but there are going to be some that aren't and those will become drones.

IRENE GARCIA NEWTON:  Yes, and also what I didn't mention before, is that workers are essentially sterile. But workers can lay eggs and then they're not fertilized, because they've never mated. So, some workers can make some drones in a colony and then you'll get this population of drones produced via the worker bees themselves and that adds to this genetic pool of potential mates for the next Queen.

KAYTE YOUNG:  Okay, well that also answers a question that I had, if [LAUGHS] workers determine that a new Queen needs to be raised, can they decide let's get some drones just in case, or whatever?

IRENE GARCIA NEWTON:  Yeah. And the other thing is that because the Queen mates with so many different drones, she produces what we call patrilines, or you may think of as like siblings groups from the same father. So, there will be drones in the colony that are more related to each other, because they share the same father and then a group of other drones that are less related, because there are different dads. So, bees of a different father will be 25% related on average, so really low relatedness. And so, there are some controversial studies out there suggesting that workers might favor a certain patriline for the next Queen if it's their patriline. So, if they share a father, maybe they want that to be [LAUGHS] the next Queen, and so they will give that larva preferentially royal jelly to try and kind of supersede.

KAYTE YOUNG:  This is the last thing I'm going to ask about the drones. [LAUGHS] So, when they leave the hive to go out, they're not foraging, they're not working?

IRENE GARCIA NEWTON:  They never do anything for the colony.

KAYTE YOUNG:  All that they're doing is trying to find some Queens.

IRENE GARCIA NEWTON:  Yeah, I got to tell you it is kind of an interesting metaphor. [LAUGHS]

KAYTE YOUNG:  I always think that when I see them, as they're huge and they're not doing anything.

IRENE GARCIA NEWTON:  And they're such a waste, my God, they just consume resources. And that's why at the end of the season, the bees kick them out. So, in the Fall you may have seen a bunch of dead drones hanging around the entrance of your colony as the workers just kick them out, because they do not want them around consuming resources when their purpose is not needed.

KAYTE YOUNG:  So, one last thing I wanted to bring up, there's been a lot in the news in the recent ten years or so, about honey bee declines and honey bee population declines, and that really what we're talking about is for commercial beekeeping, right?

IRENE GARCIA NEWTON:  I would say that the decline in honey bees is kind of a sentinel, a canary in the coal mine for the decline of all insect populations.

KAYTE YOUNG:  I guess what I was wanting to get at is that I think the way that this problem has been portrayed in the media is sort of like, "Oh, the honey bee, it's dying and this is going to be the end of our civilization" and people get really emotional about it, in part because honey bees are cute, they're fuzzy.

IRENE GARCIA NEWTON:  They dance, they produce honey.

KAYTE YOUNG:  They occupy this space.

IRENE GARCIA NEWTON:  What other insect makes a snack for you?

KAYTE YOUNG:  Right. Yeah, they're part of children's literature and mythology.

IRENE GARCIA NEWTON:  They've been with humans for thousands of years.

KAYTE YOUNG:  Yeah. So, we love them, but their species isn't particularly threatened.

IRENE GARCIA NEWTON:  They're not native. That is exactly right, so I always say, like in my analogy with chickens, it's like saying chickens are in decline and that would be important for humans, because we eat chickens, but they're not native, they're a domesticated insect. They are part of our human culture and society, but certainly not native to North America.

KAYTE YOUNG:  And the native bees might be even more threatened.

IRENE GARCIA NEWTON:  They are. Absolutely. But everything that you can do to help honeybees will also help native bees. So, I think the fact that the populous is a little charmed by this insect is not so bad for our native pollinators either. Because everything that you would suggest, reduce your use of chemicals, pesticides and herbicides in your lawn, consider not having a lawn, having a more native natural habitat. Don't cut things back in the winter to keep homes for native pollinators, for other insects. All those things that might help honeybees will help other bees and other pollinators as well.

KAYTE YOUNG:  Yeah, that makes total sense and scattering wildflower seed in medians on highways or something has got to be better for all the insects.

IRENE GARCIA NEWTON:  Instead of having a lawn, let's have more diversity, absolutely. More habitat is what all the insects need.

KAYTE YOUNG:  Okay, so if bees have to be the spokes-insect or the poster child for these needs, then all of the pollinators have them.

IRENE GARCIA NEWTON:  Yeah, absolutely.

KAYTE YOUNG:  Butterflies also can play that role because people love butterflies. [LAUGHS]

IRENE GARCIA NEWTON:  Butterflies can also, absolutely, yeah, and the statistic you hear about one in every three mouthfuls of food you consume has been pollinated by a bee, well it's been pollinated and native pollinators play a role as well in our nutrition and our agriculture.

KAYTE YOUNG:  As we were wrapping up, I asked Irene if she had any final thoughts to share.

IRENE GARCIA NEWTON:  I really like for people to know that what they eat is feeding their microbes and I don't think people think of that when they take a bite and consume it. But your diet has an amazing influence on the bacteria that live inside your gut and those bacteria are producing the most potent set of cocktails that influence everything about your body. So, thinking about that link and being more intentional about what you eat on this earth, I think is important.

KAYTE YOUNG:  That sounds like a very interesting conversation for another day.

KAYTE YOUNG:  That was Irene Garcia Newton, she's a microbiologist at Indiana University. She studies symbiosis and the microbiome of honeybee colonies. To find out more about her work, go to our website at Earth Eats dot org.

KAYTE YOUNG:  That's it for our show this week. Thanks for listening and we'll see you next time.

DANIELLA RICHARDSON:  Earth Eats is produced and edited by Kayte Young with help from Eabon Binder, Alex Chambers, Mark Chilla, Toby Foster, Samantha Gee, Abraham Hill, Payton Whaley, Harvest Public Media and me, Daniella Richardson.

KAYTE YOUNG:  Special thanks this week to Dr Irene Garcia Newton.

DANIELLA RICHARDSON:  Our theme music is composed by Erin Tobey and performed by Aaron and Matt Tobey. Additional music on the show comes to us from the artists at Universal Production Music. Our executive producer is John Bailey.

honeybees gathered on a wood surface in sunlight with shadows

Most of the bees in a hive are sterile females, called workers. They forage for resources and care for the next generation of bees inside the hive. (Kayte Young/WFIU)

“So, I like to say that bees are just like us. So bees have a society, and they live in a built environment, [they have a] little house, just like we have a little house, and they communicate through dance. I don’t know if we communicate through dance, but I think dance is also a thing that humans do…” 

On this week's show we’re talking with microbiologist Irene Garcia Newton about the beloved honeybee. We learn about the various roles within a hive, and how important diversity is in the diet of a bee.

If you know a lot about bees, you will probably find this conversation interesting because of the detailed information and discovery from a biologist who studies symbiosis, microbiota and bee nutrition.

If you don’t know much about bees, now is your chance to learn more about these complex creatures who play a crucial role in our food system.

Listen this week for a conversation with Dr. Irene Garcia Newton, she’s a professor of biology at Indiana University and her current research is focused on the honeybee. Visit the Newton Lab website to learn more about her work.

Mentioned on this episode

I Contain Multitudes, by Ed Wong 

Audrey ParishPhD candidate, IU Biology

Heather R Mattila, professor of biological sciences at Wellesley College. 

David Tarpy NC State University Apiculture Program

Robinson Lab, University of Illinois at Urbana-Champaign

A 2015 article on the study of honeybees at Indiana University (not mentioned in the interview, but there is a short video featuring Irene Newton)

Music on this episode

The Earth Eats theme music is composed by Erin Tobey and performed by Erin and Matt Tobey.

Additional music on this episode from Universal Production Music.



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